Computer programs for modelling

Question 1

Describe random errors

Answer 1

Also known as precision. The spread/standard deviation around the measured value (Seen as the standard deviation curve)

Question 2

Describe systematic errors

Answer 2

Also known as accuracy. The absolute deviation from the “true” value of a Certified Reference Material (CRM) (Seen as the distance from peak of standard deviation curve to the furthest measurement)

Question 3

What are certified reference materials (CRM)?

Answer 3

A material whose concentrations are sufficiently homogeneous and well known to be used for calibration and assessment of analytical methods.
Geological CRMs often consist of a rock or sediment that has been found suitable, and which is analyzed by a large number of high-quality laboratories.
The average concentrations obtained from this large dataset (average ± st deviation) are used as a measure of the “true” concentrations in the CRM

Question 4

What does the database contain?

Answer 4

Dissolved and solid species
Species properties
Equilibrium constant